JP2013045815A - Exposure method, and method of manufacturing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prepare correction information from a dynamic moving average.SOLUTION: Correction information for correcting a measurement result in an encoder system is found by the dynamic moving average for finding a moving average using error information on the proper number of wafers in accordance with the degree of changes in errors between the measurement results of the encoder system and an interferometer system. Thereby, since the moving average is found using a large number of error information when the change of the error (X-Xfor instance) is small (section b for instance), errors generated at random can be efficiently suppressed, and since the moving average is found using error information for a small number of wafers when the error rapidly changes (section c for instance), a delay in response attendant on an abnormal value by the moving average can be avoided.

Description

  The present invention relates to an exposure method and a device manufacturing method, and more particularly, to an exposure method for exposing an object and a device manufacturing method using the exposure method.

  Conventionally, in a lithography process for manufacturing electronic devices (microdevices) such as semiconductor elements (integrated circuits, etc.), liquid crystal display elements, etc., a step-and-repeat type projection exposure apparatus (so-called stepper) or a step-and-scan type Projection exposure apparatuses (so-called scanning steppers (also called scanners)) are mainly used.

  In this type of exposure apparatus, in order to transfer a reticle (or mask) pattern to a plurality of shot regions on a substrate such as a wafer or a glass plate (hereinafter collectively referred to as a wafer), a wafer stage that holds the wafer includes: For example, it is driven in a two-dimensional direction by a linear motor or the like. The position of the wafer stage is generally measured by using a laser interferometer having high stability over a long period of time.

  With the recent miniaturization of patterns accompanying higher integration of semiconductor elements, higher precision wafer stage position control performance has been required. For this reason, short-term fluctuations in measured values due to air fluctuations caused by the temperature change and temperature gradient of the atmosphere on the beam path of the laser interferometer cannot be ignored.

  Therefore, an invention relating to an exposure apparatus employing an encoder and a surface position measuring sensor having a measurement resolution comparable to or higher than that of a laser interferometer has been made. For example, in the exposure apparatus described in Patent Document 1, a measurement surface (that is, a reflection type diffraction grating) provided on a wafer stage is irradiated with a measurement beam, and the reflected light is detected, thereby measuring the side surface (that is, An encoder system and a surface position measurement system for measuring a displacement or a surface position of the diffraction grating of the wafer stage) with respect to the periodic direction are employed.

  However, it has recently been found that even if these measurement systems are adopted, it is difficult to achieve the measurement accuracy (and control accuracy) of the position of the wafer stage required by the next-generation exposure apparatus. did.

US Patent Application Publication No. 2008/0088843

  According to the first aspect of the present invention, there is provided an exposure method for continuously exposing a plurality of objects, wherein each time an object is exposed, a position of a moving body that holds and moves the object to be exposed is changed. Measuring the first and second position measurement systems, and exposing the object held by the moving body while driving the moving body based on the measurement result of the first position measuring system and the correction information; In parallel with the exposure, the error information about the object is created from the error between the measurement results of the first and second position measurement systems, and the exposure is completed prior to the exposure of the object to be exposed. In parallel with the exposure processing of the plurality of objects, among the error information for the plurality of objects created by the creation, the error for the appropriate number of objects according to the magnitude of the change in the error Using the information, find the moving average of the error information Determining the correction information from the moving average, and determining the correction information includes increasing the appropriate number when the change in the error is small and increasing the error when the change in the error is large. An exposure method is provided that reduces the appropriate number.

  Here, the moving average is not limited to a simple moving average, but includes other moving averages such as a load moving average and an exponential moving average.

  According to this, the first position measurement is performed by obtaining a moving average using error information on an appropriate number of objects according to the degree of change in error between the measurement results of the first and second position measurement systems. Correction information for correcting the measurement result of the system is obtained. In this case, when the change in error is small, the moving average is obtained using error information for a large number of objects, so that it is possible to efficiently suppress errors that occur randomly and to change the error. When is large, the moving average is obtained using the error information for a small number of objects, so that a response delay due to the moving average can be avoided.

  From a second aspect, the present invention is a device manufacturing method including forming a pattern on an object by the exposure method of the present invention and developing the object on which the pattern is formed.

It is a figure which shows schematically the structure of the exposure apparatus which concerns on one Embodiment. It is a top view which shows a wafer stage. It is a top view which shows arrangement | positioning of an interferometer with the wafer stage of FIG. FIG. 2 is a plan view showing an arrangement of various measuring devices (encoder, alignment system, multipoint AF system, Z head, etc.) provided in the exposure apparatus of FIG. 1. It is a top view which shows arrangement | positioning of an encoder head (X head, Y head) and an alignment system. It is a top view which shows arrangement | positioning of Z head and a multipoint AF type | system | group. It is a block diagram which shows the input / output relationship of the main controller which mainly comprises the control system of the exposure apparatus which concerns on one Embodiment. It is a figure showing the movement path | route on the wafer of an exposure center corresponding to the movement path | route of a wafer stage in exposure of a step and scan system. It is a figure showing the example of the error information calculated | required simultaneously with exposing a wafer. FIGS. 10A and 10B are diagrams showing correction information obtained from moving averages of error information of the number of samples 1 (MA1) and 10 (MA9), respectively. It is a table | surface showing the correction | amendment residual at the time of correct | amending the measurement result of an encoder system and a surface position measurement system using the correction information calculated | required from the moving average of the error information with a fixed sample number, and a dynamic moving average. FIG. 12A shows a moving average of error information (MA1 and MA10) and a graph showing correction information obtained from the dynamic moving average. FIG. 12B shows an average number of times (number of MAs) in the dynamic moving average. It is a figure which shows distribution of the frequency | count of use.

  Hereinafter, an embodiment will be described with reference to FIGS.

  FIG. 1 schematically shows a configuration of an exposure apparatus 100 according to an embodiment. The exposure apparatus 100 is a step-and-scan projection exposure apparatus, a so-called scanner. As will be described later, in the present embodiment, a projection optical system PL is provided. In the following, the direction parallel to the optical axis AX of the projection optical system PL is the Z-axis direction, and the scanning direction in which the reticle R and the wafer W are relatively scanned in a plane perpendicular to the Z-axis direction is the Y-axis direction. The direction orthogonal to the axis is defined as the X-axis direction, and the rotation (tilt) directions around the X-axis, Y-axis, and Z-axis are described as the θx, θy, and θz directions, respectively.

  The exposure apparatus 100 includes an illumination system 10, a reticle stage RST, a projection unit PU, a stage apparatus 50 having a wafer stage WST, a control system for these, and the like. In FIG. 1, wafer W is mounted on wafer stage WST.

  The illumination system 10 illuminates a slit-shaped illumination area IAR on the reticle R set (limited) with a reticle blind (also called a masking system) with illumination light (exposure light) IL with substantially uniform illuminance. The configuration of the illumination system 10 is disclosed in, for example, US Patent Application Publication No. 2003/025890. Here, as an example of the illumination light IL, ArF excimer laser light (wavelength 193 nm) is used.

  On reticle stage RST, reticle R having a circuit pattern or the like formed on its pattern surface (lower surface in FIG. 1) is fixed, for example, by vacuum suction. The reticle stage RST can be finely driven in the XY plane by a reticle stage drive system 11 (not shown in FIG. 1, refer to FIG. 7) including a linear motor, for example, and also in the scanning direction (left and right direction in FIG. 1). In the Y-axis direction) at a predetermined scanning speed.

  Position information (including rotation information in the θz direction) of reticle stage RST in the XY plane is formed on movable mirror 15 (or on the end face of reticle stage RST) by reticle laser interferometer (hereinafter referred to as “reticle interferometer”) 116. For example, with a resolution of about 0.25 nm. The measurement value of reticle interferometer 116 is sent to main controller 20 (not shown in FIG. 1, refer to FIG. 7).

  Projection unit PU is disposed below reticle stage RST in FIG. 1 and supported by a main frame (not shown). The projection unit PU includes a lens barrel 40 and a projection optical system PL held in the lens barrel 40. As the projection optical system PL, for example, a refractive optical system including a plurality of optical elements (lens elements) arranged along an optical axis AX parallel to the Z-axis direction is used. The projection optical system PL is, for example, both-side telecentric and has a predetermined projection magnification (for example, 1/4 times, 1/5 times, or 1/8 times). For this reason, when the illumination area IAR on the reticle R is illuminated by the illumination system 10, the illumination light that has passed through the reticle R arranged so that the first surface (object surface) and the pattern surface of the projection optical system PL substantially coincide with each other. Due to IL, a reduced image of the circuit pattern of the reticle R in the illumination area IAR (a reduced image of a part of the circuit pattern) passes through the projection optical system PL (projection unit PU), and the second surface of the projection optical system PL ( It is formed in an area (hereinafter also referred to as an exposure area) IA that is conjugated to the illumination area IAR on the wafer W, which is disposed on the image plane side and has a resist (sensitive agent) coated on the surface thereof. Then, by synchronous driving of reticle stage RST and wafer stage WST, reticle R is moved relative to illumination area IAR (illumination light IL) in the scanning direction (Y-axis direction) and exposure area IA (illumination light IL). By moving the wafer W relative to the scanning direction (Y-axis direction), scanning exposure of one shot area (partition area) on the wafer W is performed, and the pattern of the reticle R is transferred to the shot area. The That is, in the present embodiment, a pattern of the reticle R is generated on the wafer W by the illumination system 10 and the projection optical system PL, and the pattern is formed on the wafer W by exposure of the sensitive layer (resist layer) on the wafer W by the illumination light IL. Is formed.

  As shown in FIG. 1, stage device 50 drives wafer stage WST disposed on base board 12, measurement system 200 (see FIG. 7) for measuring positional information of wafer stage WST, and wafer stage WST. A stage drive system 124 (see FIG. 7) and the like are provided. As shown in FIG. 7, the measurement system 200 includes an interferometer system 118, an encoder system 150, a surface position measurement system 180, and the like.

  Wafer stage WST is supported above base plate 12 through a gap (gap / clearance) of about several μm by a non-contact bearing (not shown) such as an air bearing. Wafer stage WST can be driven with a predetermined stroke in the X-axis direction and the Y-axis direction by stage drive system 124 (see FIG. 7) including a linear motor and the like.

  Wafer stage WST includes a stage main body 91 and a wafer table WTB mounted on stage main body 91. Wafer table WTB and stage main body 91 are moved in a direction of six degrees of freedom (X axis, Y axis, Z axis, etc.) with respect to base board 12 by a drive system including a linear motor and a Z / leveling mechanism (including a voice coil motor). It can be driven in each direction of θx, θy, and θz.

  At the center of the upper surface of wafer table WTB, a wafer holder (not shown) for holding wafer W by vacuum suction or the like is provided. As shown in FIG. 2, a measurement plate 30 is provided on the + Y side of the wafer holder (wafer W) on the upper surface of wafer table WTB. The measurement plate 30 is provided with a reference mark FM at the center, and a pair of aerial image measurement slit plates SL on both sides of the reference mark FM in the X-axis direction. As an example, each aerial image measurement slit plate SL has a linear opening pattern (X slit) having a predetermined width (for example, 0.2 μm) whose longitudinal direction is the Y-axis direction, and the longitudinal direction is the X-axis direction. A line-shaped opening pattern (Y slit) having a predetermined width (for example, 0.2 μm) is formed.

  Corresponding to each aerial image measurement slit plate SL, inside the wafer table WTB is an optical system including a lens and a light receiving element such as a photomultiplier tube (photomultiplier tube (PMT)). A pair of aerial image measuring devices 45A and 45B (see FIG. 7) similar to those disclosed in US Patent Application Publication No. 2002/0041377 and the like are provided. The measurement results (output signals of the light receiving elements) of the aerial image measurement devices 45A and 45B are subjected to predetermined signal processing by a signal processing device (not shown) and sent to the main control device 20 (see FIG. 7).

Further, a scale used in an encoder system to be described later is disposed on the upper surface of wafer table WTB. More specifically, Y scales 39Y ₁ and 39Y ₂ are fixed to regions on one side and the other side of the upper surface of wafer table WTB in the X-axis direction (left and right direction in FIG. 2). The Y scales 39Y ₁ and 39Y ₂ are, for example, reflective type gratings (for example, diffraction gratings) in which the Y axis direction is a periodic direction in which grid lines 38 having the X axis direction as the longitudinal direction are arranged at a predetermined pitch in the Y axis direction. ).

Similarly, X scale 39X ₁ , X scale 39X ₁ , and Y scale 39Y ₁ and 39Y ₂ are sandwiched between one side and the other side in the Y-axis direction (up and down direction in the drawing in FIG. 2) of wafer table WTB. 39X ₂ are fixed respectively. The X scales 39X ₁ and 39X ₂ are, for example, reflection type gratings (for example, diffraction gratings) in which the X-axis direction is a periodic direction in which grid lines 37 having a longitudinal direction in the Y-axis direction are arranged in the X-axis direction at a predetermined pitch. ).

  The pitch of the grid lines 37 and 38 is set to 1 μm, for example. In FIG. 2 and other figures, the pitch of the grating is shown larger than the actual pitch for convenience of illustration.

  It is also effective to cover the diffraction grating with a glass plate having a low coefficient of thermal expansion. Here, as the glass plate, a glass plate having the same thickness as that of the wafer, for example, a thickness of 1 mm can be used, and the surface of the glass plate is the same height (same surface) as the wafer surface. Installed on top of table WTB.

  Further, as shown in FIG. 2, a reflecting surface 17a and a reflecting surface 17b used in an interferometer system to be described later are formed on the −Y end surface and the −X end surface of the wafer table WTB.

  Further, on the surface on the + Y side of wafer table WTB, as shown in FIG. 2, a fiducial extending in the X-axis direction is the same as the CD bar disclosed in US Patent Application Publication No. 2008/0088843. A bar (hereinafter abbreviated as “FD bar”) 46 is attached. Reference gratings (for example, diffraction gratings) 52 having a periodic direction in the Y-axis direction are formed in the vicinity of one end and the other end in the longitudinal direction of the FD bar 46 in a symmetrical arrangement with respect to the center line LL. . A plurality of reference marks M are formed on the upper surface of the FD bar 46. As each reference mark M, a two-dimensional mark having a size detectable by an alignment system described later is used.

In the exposure apparatus 100 of the present embodiment, as shown in FIGS. 4 and 5, the optical axis on a straight line (hereinafter referred to as a reference axis) LV parallel to the Y axis passing through the optical axis AX of the projection optical system PL. A primary alignment system AL1 having a detection center is arranged at a position a predetermined distance from AX on the -Y side. Primary alignment system AL1 is fixed to the lower surface of the main frame (not shown). As shown in FIG. 5, secondary alignment systems AL2 ₁ and AL2 _{2 in} which detection centers are arranged almost symmetrically with respect to the reference axis LV on one side and the other side in the X-axis direction across the primary alignment system AL1. , AL2 ₃ and AL2 ₄ are provided. The secondary alignment systems AL2 _{1 to} AL2 ₄ are fixed to the lower surface of the main frame (not shown) via a movable support member, and the drive mechanisms 60 _{1 to} 60 ₄ (see FIG. 7) are used for the X-axis direction. The relative positions of these detection areas can be adjusted.

In this embodiment, as each of the alignment systems AL1, AL2 _{1 to} AL2 ₄ , for example, an image processing system FIA (Field Image)
Alignment) system is used. Imaging signals from each of the alignment systems AL1, AL2 _{1 to} AL2 ₄ are supplied to the main controller 20 via a signal processing system (not shown).

As shown in FIG. 3, interferometer system 118 irradiates reflecting surface 17a or 17b with an interferometer beam (length measuring beam), receives the reflected light, and positions wafer stage WST in the XY plane. Y interferometer 16, three X interferometers 126 to 128, and a pair of Z interferometers 43A and 43B. More specifically, the Y interferometer 16 reflects at least three length measuring beams parallel to the Y axis including a pair of length measuring beams B4 ₁ and B4 ₂ symmetric with respect to the reference axis LV, and a movable mirror 41 described later. Irradiate. Further, as shown in FIG. 3, the X interferometer 126 includes a pair of length measuring beams symmetrical with respect to a straight line (hereinafter referred to as a reference axis) LH parallel to the X axis orthogonal to the optical axis AX and the reference axis LV. B5 _1, B5 parallel measurement beam into at least three X-axis including ₂ irradiates the reflecting surface 17b. The X interferometer 127 includes a length measurement beam B6 having a length measurement axis as a straight line (hereinafter referred to as a reference axis) LA parallel to the X axis orthogonal to the reference axis LV at the detection center of the primary alignment system AL1. At least two measurement beams parallel to the Y axis are applied to the reflecting surface 17b. Further, the X interferometer 128 irradiates the reflection surface 17b with a measurement beam B7 parallel to the Y axis.

  Position information from each interferometer of the interferometer system 118 is supplied to the main controller 20. Based on the measurement results of Y interferometer 16 and X interferometer 126 or 127, main controller 20 rotates in the θx direction (ie, pitching), θy in addition to the X and Y positions of wafer table WTB (wafer stage WST). Rotation in the direction (ie rolling) and rotation in the θz direction (ie yawing) can also be calculated.

  As shown in FIG. 1, a movable mirror 41 having a concave reflecting surface is attached to the side surface on the −Y side of the stage main body 91. As can be seen from FIG. 2, the movable mirror 41 is longer in the X-axis direction than the reflecting surface 17a of the wafer table WTB.

  A pair of Z interferometers 43A and 43B that constitute part of the interferometer system 118 (see FIG. 7) are provided facing the movable mirror 41 (see FIGS. 1 and 3). The Z interferometers 43A and 43B irradiate the movable mirror 41 with two measuring beams B1 and B2 parallel to the Y axis, respectively, and pass the measuring beams B1 and B2 through the moving mirror 41 to the main frame, for example. Irradiate to fixed mirrors 47A and 47B fixed to (not shown). And each reflected light is received and the optical path length of length measuring beam B1, B2 is measured. From the result, main controller 20 calculates the position of wafer stage WST in the four-degree-of-freedom direction (the Y-axis, Z-axis, θy, and θz directions).

  In the exposure apparatus 100 of the present embodiment, a plurality of encoder systems 150 are configured to measure the position (X, Y, θz) in the XY plane of the wafer stage WST independently of the interferometer system 118. A head unit is provided.

As shown in FIG. 4, four head units 62A, 62B, 62C, and 62D are arranged on the + X side, + Y side, -X side of the projection unit PU, and -Y side of the primary alignment system AL1, respectively. ing. Head units 62E and 62F are provided on both outer sides in the X-axis direction of the alignment systems AL1, AL2 _{1 to} AL2 ₄ , respectively. The head units 62A to 62F are fixed in a suspended state to a main frame (not shown) via support members. In FIG. 4, symbol UP indicates an unloading position at which a wafer on wafer stage WST is unloaded, and symbol LP indicates a loading position at which a new wafer is loaded on wafer stage WST. Show.

As shown in FIG. 5, the head units 62 </ b> A and 62 </ b> C include a plurality (here, five) of Y heads 65 _{1 to} 65 ₅ and Y heads 64 ₁ to 64 arranged at the interval WD on the reference axis LH. ₅ is provided. Hereinafter, Y heads 65 _{1 to} 65 ₅ and Y heads 64 ₁ to 64 ₅ are also referred to as Y head 65 and Y head 64, respectively, as necessary.

The head units 62A and 62C use the Y scales 39Y ₁ and 39Y ₂ to measure the position (Y position) of the wafer stage WST (wafer table WTB) in the Y-axis direction (multi-lens Y linear encoders 70A and 70C). 7). In the following, the Y linear encoder is abbreviated as “Y encoder” or “encoder” as appropriate.

As shown in FIG. 5, the head unit 62B is arranged on the + Y side of the projection unit PU, and includes a plurality of (here, four) X heads 66 _{5 to} 66 ₈ arranged on the reference axis LV at intervals WD. I have. Further, head unit 62D is arranged on the -Y side of primary alignment system AL1, a plurality which are arranged at a distance WD on reference axis LV (four in this case) and a X heads 66 ₁ to 66 _4. Hereinafter, the X heads 66 _{5 to} 66 ₈ and the X heads 66 _{1 to} 66 ₄ are also referred to as the X head 66 as necessary.

The head units 62B and 62D use X scales 39X ₁ and 39X ₂ to measure the position (X position) of the wafer stage WST (wafer table WTB) in the X-axis direction (X position). 7). In the following, the X linear encoder is abbreviated as “encoder” as appropriate.

Here, the interval WD in the X-axis direction of the five Y heads 65 and 64 (more precisely, the irradiation points on the scale of the measurement beam emitted by the Y heads 65 and 64) provided in the head units 62A and 62C, respectively. At the time of exposure or the like, it is determined that at least one head always faces the corresponding Y scales 39Y ₁ and 39Y ₂ (irradiates the measurement beam). Similarly, the interval WD in the Y-axis direction between adjacent X heads 66 (more precisely, the irradiation points on the scale of the measurement beam emitted by the X head 66) provided in the head units 62B and 62D is determined during exposure. , It is determined that at least one head always faces the corresponding X scale 39X ₁ or 39X ₂ (irradiates the measurement beam).

The distance between the most + Y side X heads 66 ₄ of the most -Y side of the X heads 66 ₅ and the head unit 62D of the head unit 62B is the movement of the Y-axis direction of wafer stage WST, between the two X heads The width of the wafer table WTB is set to be narrower than the width in the Y-axis direction so that it can be switched (connected).

Head unit 62E, as shown in FIG. 5, a Y heads _67i to 674 ₄ of the plurality of (four in this case).

Head unit 62F is equipped with a Y heads 68 ₁ to 68 ₄ of a plurality (four in this case). Y heads 68 ₁ to 68 _4, with respect to the reference axis LV, is disposed on the Y head 67 _{4-67 1} and symmetrical position. In the following, optionally, the Y head 67 _{4-67 1} and Y heads 68 ₁ to 68 _4, denoted respectively both Y heads 67 and Y heads 68.

At the time of alignment measurement, at least one Y head 67 and 68 faces the Y scales 39Y ₂ and 39Y ₁ , respectively. The Y position (and θz rotation) of wafer stage WST is measured by Y heads 67 and 68 (that is, Y encoders 70E and 70F (see FIG. 7) configured by Y heads 67 and 68).

In this embodiment, the Y heads 67 ₃ and 68 ₂ that are adjacent to the secondary alignment systems AL2 ₁ and AL2 ₄ in the X-axis direction at the time of measuring the baseline of the secondary alignment system, etc. The Y positions of the FD bar 46 are measured at the positions of the respective reference gratings 52 by the Y heads 67 ₃ and 68 ₂ facing the gratings 52 and facing the pair of reference gratings 52, respectively. Hereinafter, encoders configured by Y heads 67 ₃ and 68 ₂ respectively facing the pair of reference gratings 52 are referred to as Y linear encoders 70E ₂ and 70F ₂ . For identification, the Y encoder constituted by the Y heads 67 and 68 facing the Y scales 39Y ₂ and 39Y ₁ is referred to as Y encoders 70E ₁ and 70F ₁ .

Encoder system 150 encoder 70A~70F of each head constituting the (see FIG. 7) (64 ₁ to 64 _5, 65 ₁ to 65 _5, 66 ₁ to 66 _8, 67 ₁ to 67 _4, 68 ₁ to 68 ₄₎ For example, the diffraction interference type encoder head disclosed in US Pat. No. 7,238,931, US Patent Application Publication No. 2008/0088843, and the like can be used. In this type of encoder head, two measurement beams are irradiated onto the corresponding scales, the respective return lights are combined and received as one interference light, the intensity of the interference light is detected by a photodetector, and the interference is detected. The displacement of the scale in the measurement direction (period direction of the diffraction grating) is measured from the change in light intensity.

The measured values of the encoders 70A to 70F described above are supplied to the main controller 20. Main controller 20 determines position (X) of wafer stage WST in the XY plane based on the measurement values of three of encoders 70A to 70D or three of encoders 70E ₁ , 70F ₁ , 70B and 70D. , Y, θz). Main controller 20 controls the rotation of FD bar 46 (wafer stage WST) in the θz direction based on the measurement values of linear encoders 70E ₂ and 70F ₂ .

  Furthermore, in the exposure apparatus 100 of the present embodiment, as shown in FIGS. 4 and 6, a multipoint focal position detection system (hereinafter referred to as “multipoint AF system”) including an irradiation system 90a and a light receiving system 90b. ) Is provided. As the multipoint AF system, for example, an oblique incidence system having the same configuration as that disclosed in US Pat. No. 5,448,332 is adopted. In the present embodiment, as an example, the irradiation system 90a is disposed on the + Y side of the −X end portion of the head unit 62E described above, and light is received on the + Y side of the + X end portion of the head unit 62F while facing this. A system 90b is arranged. The multipoint AF system (90a, 90b) is fixed to the lower surface of the main frame.

  In FIG. 4 and FIG. 6, a plurality of detection points irradiated with the detection beam are not shown individually, but as elongated detection areas (beam areas) AF extending in the X-axis direction between the irradiation system 90a and the light receiving system 90b. It is shown. Since the detection area AF is set to have a length in the X-axis direction that is approximately the same as the diameter of the wafer W, the wafer W is scanned almost in the Y-axis direction once in the Z-axis direction. Position information (surface position information) can be measured.

  As shown in FIG. 6, each pair of pairs constituting a part of the surface position measurement system 180 is arranged in the vicinity of both ends of the detection area AF of the multipoint AF system (90a, 90b) in a symmetrical arrangement with respect to the reference axis LV. Heads for Z position measurement (hereinafter abbreviated as “Z head”) 72a, 72b and 72c, 72d are provided. These Z heads 72a to 72d are fixed to the lower surface of a main frame (not shown).

As the Z heads 72a to 72d, for example, a head of an optical displacement sensor similar to an optical pickup used in a CD drive device or the like is used. Z heads 72a to 72d irradiate wafer table WTB with a measurement beam from above, receive the reflected light, and measure the surface position of wafer table WTB at the irradiation point. In the present embodiment, the measurement beam of the Z head is reflected by the surface of the reflection type diffraction grating constituting the Y scales 39Y ₁ and 39Y ₂ described above.

Further, as shown in FIG. 6, the head units 62A and 62C described above are in the same X position as the five Y heads 65 _j and 64 _i (i, j = 1 to 5) provided in the head units 62A and 62C. The five Z heads 76 _j and 74 _i (i, j = 1 to 5) are provided while being shifted. The five Z heads 76 _j and 74 _i belonging to the head units 62A and 62C are arranged symmetrically with respect to the reference axis LV. Incidentally, as each Z head 76 _j, 74 _i, the head of the same optical displacement sensor as described above for Z head 72a~72d is used.

Above Z heads 72a to 72d, 74 to _72d, 76 ₁ to 76 _5, as shown in FIG. 7, are connected to the main controller 20 via the signal processing and selection device 170, the main control device 20, Z head 72a~72d via signal processing and selection device 170, and 74 to _72d, 76 ₁ to 76 operating condition by selecting any Z head from _five, and its operating state Surface position information detected by the Z head is received via the signal processing / selection device 170. In this embodiment, Z head _{72a~72d, 74 1 ~74 5, 76} 1 ~76 5 and the position information of the tilt direction and a signal processing and selection device 170 with respect to the Z-axis direction and the XY plane of wafer stage WST A surface position measurement system 180 is measured.

  In the present embodiment, main controller 20 uses surface position measurement system 180 (see FIG. 7), in an effective stroke area of wafer stage WST, that is, in an area where wafer stage WST moves for exposure and alignment measurement. The position coordinates in the two-degree-of-freedom direction (Z, θy) are measured.

  FIG. 7 is a block diagram showing the input / output relationship of the main controller 20 that centrally configures the control system of the exposure apparatus 100 and performs overall control of each component. The main controller 20 includes a workstation (or a microcomputer) and the like, and comprehensively controls each part of the exposure apparatus 100.

In the exposure apparatus 100 of the present embodiment configured as described above, the unloading position UP (in accordance with a procedure similar to the procedure disclosed in the embodiment of US Patent Application Publication No. 2008/0088843, for example. The unloading of the wafer W at the loading position LP (see FIG. 4), the loading of the new wafer W onto the wafer table WTB at the loading position LP (see FIG. 4), the reference mark FM of the measurement plate 30 and the primary alignment system AL1 are used. The first half of the baseline check of the primary alignment system AL1, the resetting of the origin of the encoder system and the interferometer system, the alignment measurement of the wafer W using the alignment systems AL1, AL2 _{1 to} AL2 ₄ , and in parallel with this Focus mapping, aerial image measuring device 45A, 4 Step-and-scan based on the processing of the second half of the baseline check of the primary alignment system AL1 using B, the positional information of each shot area on the wafer obtained as a result of alignment measurement, and the latest alignment system baseline A series of processing using wafer stage WST, such as exposure of a plurality of shot areas on wafer W in the system, is executed by main controller 20. Detailed description is omitted.

The baseline measurement of the secondary alignment systems AL2 _{1 to} AL2 ₄ is performed at an appropriate timing by the encoders 70E ₂ and 70F ₂ described above in the same manner as the method disclosed in US Patent Application Publication No. 2008/0088843. Based on the measured value, the reference mark M on the FD bar 46 in each field of view is adjusted using the alignment systems AL1, AL2 _{1 to} AL2 ₄ with the θz rotation of the FD bar 46 (wafer stage WST) adjusted. It is done by measuring simultaneously.

  Next, error correction of measurement results of the encoder system 150 and the surface position measurement system 180 in the exposure apparatus 100 of the present embodiment will be described.

  When the main controller 20 exposes the wafer W by the step-and-scan method, in parallel with this, it creates error information of the measurement results of the encoder system 150 and the surface position measurement system 180. Here, in order to create error information, the interferometer system 118 is employed as a reference measurement system.

  In the exposure, main controller 20 includes an X head, a Y head, and a surface that face the X scale and the Y scale as the wafer stage WST moves, among a plurality of X heads and Y heads constituting encoder system 150. The position (X, Y, Z) of wafer stage WST is measured using the Z head that faces the Y scale as wafer stage WST moves among the plurality of Z heads constituting position measurement system 180. Based on the result, main controller 20 drives wafer stage WST in the X-axis direction, the Y-axis direction, and the Z-axis direction. In the following, for simplification of description, it is assumed that main controller 20 measures position (X, Y, Z) of wafer stage WST using encoder system 150 and surface position measurement system 180.

It is assumed that the movement path of wafer stage WST in step-and-scan exposure is uniquely determined according to the shot map (size and arrangement of shot areas) of wafer W. FIG. 8 shows, as an example, a moving path of wafer stage WST in the above-described exposure for wafer W having 26 shot areas S _m (m = 1 to 26). This movement path is a movement path (hereinafter referred to as movement path BE) from the start position B to the end position E of the exposure center (center of the exposure area IA). In step-and-scan exposure, the exposure center moves relative to the wafer W from the start position B to the end position E along the movement path BE without stopping. Actually, the exposure center is fixed, and the wafer W moves along a path opposite to the movement path BE. Here, for the sake of easy understanding, the exposure center is moved to the movement path BE. Along the wafer W.

In a linear section parallel to the Y axis shown by the solid line in FIG. 8, wafer stage WST is driven at a constant speed in order to scan and expose each shot area. In a curved section indicated by a broken line connecting the straight sections, the scanning exposure for a certain shot area S _m is completed, and the scanning exposure for the next shot area S _{m + 1} is started. Stepping drive in the axial direction). In parallel with this stepping, wafer stage WST is decelerated to zero speed in the scanning direction and further accelerated in the opposite direction.

Main controller 20 drives wafer stage WST along the above-described movement path BE (a path on the corresponding stage coordinates), and at the same time, uses interferometer system 118 to position (X ₀ , Y _{0) of} wafer stage WST. , Z ₀ ) and the difference between the measurement results (X, Y, Z) of the encoder system 150 with respect to the measurement results, that is, errors (X−X ₀ , Y−Y ₀ , Z−Z). ₀ ). Here, the main controller 20 performs a measurement clock generation cycle (Δt = about 100 μsec) during a time period for performing exposure processing of one wafer W by step-and-scan exposure, for example, about 10 seconds. Record the error in Accordingly, error information that is a set of 10 ⁵ errors (X−X ₀ , Y−Y ₀ , Z−Z ₀ ) is obtained for one wafer. Note that the amount of information may be reduced by averaging the error information for each shot area, or by thinning out, depending on computer resources, accuracy required for correction, and the like. The error information is a set W ⁽ⁿ of discrete values of errors (X−X ₀ , Y−Y ₀ , Z−Z ₀ ) _i for the measurement point i (= 1 to 10 ⁵ ) for the n-th wafer. ⁾ _I = (X−X ₀ , YY ₀ , Z−Z ₀ ) _i (i = 1 to 10 ⁵ )

Since the movement path of wafer stage WST is uniquely determined as described above, measurement point i (= 1 to 10 ⁵ ) can be read as a position on movement path BE. Therefore, main controller 20 records the error information as a function of position on travel path BE (in map format).

In FIG. 9, as an example, an example of fluctuations in error information (X−X ₀ ) related to X position measurement is shown with the horizontal axis as time. As shown in FIG. 9, the error information (X−X ₀ ), that is, the signal waveform corresponding thereto, gradually changes (for example, increases) in the section a, and maintains a substantially constant state in the section b. In section c, there is a rapid change (increase / decrease). In this way, even if it is said to be a fluctuation, the waveform varies in various ways, and there are times when the change is severe and there are times when it is stable.

Main controller 20 records error information W ⁽ⁿ⁾ _i for all wafers to be exposed. The main controller 20 averages some of the recorded error information W ⁽ⁿ⁾ _i , especially a moving average (simple movement ⁾ of the error information W ⁽ⁿ⁾ _i for the most recently exposed wafers. By averaging), correction information Δ _i = (ΔX _i , ΔY _i , ΔZ _i ) for correcting the measurement results (X, Y, Z) of the encoder system 150 and the surface position measurement system 180 is obtained.

FIGS. 10A and 10B show error information W ⁽ⁿ⁾ _i obtained for a wafer 290 to 390th (n = 290 to 390) exposed for a certain measurement point _i . Variations are shown. As shown by circles in FIG. 10A, it can be seen that randomly generated errors (random errors) frequently occur. Accordingly, when the correction information is obtained using the error information, if the random error is not removed, a correction error is generated due to the random error, leading to a decrease in measurement accuracy. Therefore, the moving average is obtained using error information about a large number (number of samples) of wafers. In this embodiment, the moving average of a large number of samples is obtained, and correction information in which random errors are suppressed by the averaging effect. Is determined.

In FIGS. 10A and 10B, correction information (represented as “Correction value” in the figure) obtained from the moving average of error information of the number of samples 1 (MA1) and 10 (MA9), respectively. Error information (in the figure, "real
value ”) and plotted. As is clear from FIG. 10A, when the number of samples is 1, random errors are taken into the correction information without being averaged. On the other hand, as is clear from FIG. 10B, it is understood that when the number of samples is 10, random errors are averaged and are hardly taken into the correction information.

  As described above, by obtaining correction information from a moving average of a large number of samples, correction information in which random errors are suppressed can be obtained. However, on the other hand, when a jump value occurs, a correction error occurs and a recovery delay occurs.

Therefore, in the present embodiment, a dynamic moving average is used in which the number of moving average samples is adjusted according to the degree of change in error information. As a result, when the change of the error information W ⁽ⁿ⁾ _i is small, for example, a moving average of the error information is obtained using many samples in the interval b in FIG. 9, and when the change of the error information W ⁽ⁿ⁾ _i is large, For example, in section c in FIG. 9, a moving average of error information is obtained using error information of a few samples.

Assuming that a plurality (n) of wafers are exposed and error information W ^{(n ′)} _i (n ′ = 1 to n, i = 1 to 10 ⁵ ) is recorded, the error information is corrected by dynamic moving average. The creation of information will be described.

Main controller 20 uses, as reference information, error information W ⁽ⁿ⁾ _i for the ^nth (most recently) exposed wafer among the plurality of wafers, and from n−1 to n−k of the plurality of wafers. The average AW ^{(n−1 to nk)} _i of error information W ^(n−j) _i (j = 1 ^{to k)} _i = (1 / k) Σ _j = _{1 to k} w ^(n−j) _i is used to shift ε _ki = AW ^{(n−1 to n−k)} _i −W ⁽ⁿ⁾ _i for k = 1 to K (for example, K = 10). Ask. The main controller 20 selects a value of k that gives the least square value ε _ki ² from the obtained deviation ε _ki (k = 1 to K). Using the value of k, correction information Δ ^{(n + 1)} _i = 1 / (k + 1) Σ _j = 0 to _kW ^(n−j) _i is obtained.

Main controller 20 obtains correction information Δ ^{(n + 1)} _i as described above every time the wafer is exposed, records the result, and also records the value of k that gives the least square value ε _ki ² . Here, the correction information Δ ^{(n + 1)} _i is obtained by using the intermediate value of the nearest odd number of the recorded values (value of k) instead of the value of k giving the least square value. It is also good. Thereby, the jump value of the value of k which gives the least square value can be removed.

  FIG. 11 shows a correction residual (residual after correction) when a moving average (MA1 to MA9) and a dynamic moving average (dynamic MA) of 1 to 9 are used with a fixed average number (number of samples-1). Error). From the table of FIG. 11, it can be seen that when a moving average with a fixed average number is used, the correction residual tends to be improved as the number of samples (average number) increases. On the other hand, it can be seen that the correction residual when the dynamic moving average (dynamic MA) is used is smaller than the correction residual of MA9.

  FIG. 12 (A) shows moving averages MA1 and MA10 having an average number of times 1 and 10 for the wafer (n = 109 to 154) exposed from the 109th to the 154th (and for a plurality of measurement points i). And the correction information obtained by the dynamic moving average of this embodiment are plotted. The correction information obtained from MA1 has a large degree of variation because random errors are not suppressed. On the other hand, the correction information obtained from the MA 10 suppresses random errors and has a small degree of variation. However, it can be seen that the effect of the jump value generated on the correction information for the 130th wafer appears in the correction information for the 131st to 139th wafers, and a delay in the recovery occurs. On the other hand, in the correction information obtained by the dynamic moving average according to the present embodiment, the random error is suppressed and the degree of variation is small as in the correction information obtained from the MA 10. Further, it can be seen that the influence of the jump value generated on the correction information for the 130th wafer does not appear in the correction information for the 132nd wafer and is quickly recovered.

  FIG. 12B shows the distribution of the number of uses for each average number of times (the number of MAs) in the dynamic moving average. MA10 is the most, and most is MA6 or more. Therefore, it can be seen that the random error is efficiently suppressed in the dynamic moving average. On the other hand, although it is slight, MA4 or less can also be confirmed. This is accompanied by a rare jump value, and it is expected that a delay in response is avoided.

Main controller 20 measures position (X, Y, Z) of wafer stage WST using encoder system 150 and surface position measurement system 180 in the exposure of the next (n + 1) th wafer, and a correction corresponding to the result. Based on the information Δ ^{(n + 1)} _i = (ΔX ^{(n + 1)} _i , ΔY ^{(n + 1)} _i , ΔZ ^{(n + 1)} _i ), in other words, (X−ΔX ^{(n + 1)} _i , Y−ΔY ^{(n + 1)} _i , Z−ΔZ ^{(n + 1)} _i ), the wafer stage WST is driven to expose the ^{(n + 1)} th wafer. Here, a value corresponding to the measurement time (or a position on the movement route BE) is selected as the value of i.

  As described in detail above, according to the exposure apparatus 100 of the present embodiment, the degree of change in error between the measurement results of the encoder system 150 and the surface position measurement system 180 and the interferometer system 118 by the main controller 20. Accordingly, a moving average is obtained using error information for an appropriate number of wafers, and correction information for correcting the measurement results of the encoder system 150 and the surface position measuring system 180 is obtained from the moving average. When the change in error is small, main controller 20 obtains a moving average using error information for a large number of wafers, so that it is possible to efficiently suppress errors that occur randomly, When the change in error is large, the moving average is obtained using error information for a small number of wafers, so that it is possible to avoid a delay in response due to a jump value due to the moving average.

  In this embodiment, the simple moving average is adopted as the moving average. However, the moving average is not limited to this, and other moving averages such as a load moving average and an exponential moving average can also be adopted.

Further, in the exposure apparatus 100 of the present embodiment, correction information is obtained from the moving average using a combination of error information that gives the least square value ε _ki ^2. Therefore, when the change in error is small, a lot of error information is obtained. It is possible to efficiently determine the error that occurs randomly, and when the change in error is large, the moving average is obtained using a small amount of error information. It becomes possible to suppress a delay in response due to the jump value due to.

  Of course, the configurations of the encoder system and the surface position measurement system described in the above embodiment are merely examples. For example, in the above-described embodiment, an encoder system having a configuration in which a grating portion (Y scale, X scale) is provided on a wafer table (wafer stage) and a Y head and an X head are disposed outside the wafer stage so as to face the lattice portion. Although the case where it is adopted is exemplified, the present invention is not limited to this. For example, as disclosed in US Patent Application Publication No. 2006/0227309, an encoder head is provided on the wafer stage, and the wafer stage is opposed to the encoder head. You may employ | adopt the encoder system of the structure which arrange | positions a grating | lattice part (For example, the two-dimensional grating | lattice or the two-dimensionally arranged one-dimensional grating | lattice part) outside. In this case, the Z head may also be provided on the wafer stage, and the surface of the lattice portion may be a reflective surface to which the measurement beam of the Z head is irradiated. Also, when a lattice portion is provided on a wafer table (wafer stage), a two-dimensional lattice may be provided.

  In the above-described embodiment, for example, the case where the encoder head and the Z head are separately provided in the head units 62A and 62C has been described. However, a single unit having the functions of the encoder head and the Z head has been described. The head may be used in place of a set of encoder head and Z head. As such a head, for example, a displacement measuring sensor head disclosed in US Pat. No. 7,561,280 can be used.

  In the above-described embodiment, the case where the exposure apparatus is a dry type exposure apparatus that exposes the wafer W without using liquid (water) has been described. 49504, European Patent Application No. 1420298, US Patent No. 6,952,253, US Patent Application Publication No. 2008/0088843, etc. The above embodiment can also be applied to an exposure apparatus that forms an immersion space including an optical path of illumination light between the two and exposes the wafer with illumination light through the projection optical system and the liquid in the immersion space.

  In the above-described embodiment, the case where the exposure apparatus is a step-and-scan scanning exposure apparatus has been described. However, the present invention is not limited to this, and a step-and-stitch system that combines a shot area and a shot area is used. The above-described embodiments can also be applied to other reduced projection exposure apparatuses, proximity type exposure apparatuses, mirror projection aligners, and the like. Further, as disclosed in, for example, US Pat. No. 6,590,634, US Pat. No. 5,969,441, US Pat. No. 6,208,407, etc. The above-described embodiment can also be applied to a multi-stage type exposure apparatus including a stage.

  Further, the projection optical system in the exposure apparatus of the above embodiment may be not only a reduction system but also any of the same magnification and enlargement systems, and the projection optical system PL may be any of a reflection system and a catadioptric system as well as a refraction system. The projected image may be either an inverted image or an erect image. In addition, the illumination area and the exposure area described above are rectangular in shape, but the shape is not limited to this, and may be, for example, an arc, a trapezoid, or a parallelogram.

The light source of the exposure apparatus of the above embodiment is not limited to the ArF excimer laser, but is a KrF excimer laser (output wavelength 248 nm), F ₂ laser (output wavelength 157 nm), Ar ₂ laser (output wavelength 126 nm), Kr ₂ laser ( It is also possible to use a pulse laser light source with an output wavelength of 146 nm, an ultrahigh pressure mercury lamp that emits a bright line such as g-line (wavelength 436 nm), i-line (wavelength 365 nm), and the like. A harmonic generator of a YAG laser or the like can also be used. In addition, as disclosed in, for example, US Pat. No. 7,023,610, a single wavelength laser beam in an infrared region or a visible region oscillated from a DFB semiconductor laser or a fiber laser is used as vacuum ultraviolet light. For example, a harmonic that is amplified by a fiber amplifier doped with erbium (or both erbium and ytterbium) and wavelength-converted into ultraviolet light using a nonlinear optical crystal may be used.

  In the above embodiment, it is needless to say that the illumination light IL of the exposure apparatus is not limited to light having a wavelength of 100 nm or more, and light having a wavelength of less than 100 nm may be used. For example, in recent years, in order to expose a pattern of 70 nm or less, EUV (Extreme Ultraviolet) light in a soft X-ray region (for example, a wavelength region of 5 to 15 nm) is generated using an SOR or a plasma laser as a light source, and its exposure wavelength Development of an EUV exposure apparatus using an all-reflection reduction optical system designed under (for example, 13.5 nm) and a reflective mask is underway. In this apparatus, a configuration in which scanning exposure is performed by synchronously scanning the mask and the wafer using arc illumination is conceivable. Therefore, the above embodiment can be suitably applied to such an apparatus. In addition, the above embodiment can be applied to an exposure apparatus that uses charged particle beams such as an electron beam or an ion beam.

  In the above-described embodiment, a light transmission mask (reticle) in which a predetermined light-shielding pattern (or phase pattern / dimming pattern) is formed on a light-transmitting substrate is used. Instead of this reticle, For example, as disclosed in US Pat. No. 6,778,257, an electronic mask (variable shaping mask, which forms a transmission pattern, a reflection pattern, or a light emission pattern based on electronic data of a pattern to be exposed, as disclosed in US Pat. No. 6,778,257. For example, a non-light emitting image display element (spatial light modulator) including a DMD (Digital Micro-mirror Device) may be used.

  For example, the above-described embodiment can be applied to an exposure apparatus (lithography system) that forms line and space patterns on a wafer by forming interference fringes on the wafer.

  Further, as disclosed in, for example, US Pat. No. 6,611,316, two reticle patterns are synthesized on a wafer via a projection optical system, and one scan exposure is performed on one wafer. The above embodiment can also be applied to an exposure apparatus that performs double exposure of shot areas almost simultaneously.

  Note that the object on which the pattern is to be formed in the above embodiment (the object to be exposed to the energy beam) is not limited to the wafer, but other objects such as a glass plate, a ceramic substrate, a film member, or a mask blank. But it ’s okay.

  The use of the exposure apparatus is not limited to the exposure apparatus for semiconductor manufacturing. For example, an exposure apparatus for liquid crystal that transfers a liquid crystal display element pattern onto a square glass plate, an organic EL, a thin film magnetic head, an image sensor ( CCDs, etc.), micromachines, DNA chips and the like can also be widely applied to exposure apparatuses. Further, in order to manufacture reticles or masks used in not only microdevices such as semiconductor elements but also light exposure apparatuses, EUV exposure apparatuses, X-ray exposure apparatuses, electron beam exposure apparatuses, etc., glass substrates or silicon wafers, etc. The above embodiment can also be applied to an exposure apparatus that transfers a circuit pattern.

  An electronic device such as a semiconductor element includes a step of designing a function / performance of the device, a step of manufacturing a reticle based on the design step, a step of manufacturing a wafer from a silicon material, and the exposure apparatus (pattern forming apparatus) of the above-described embodiment. ) A lithography step for transferring a mask (reticle) pattern onto a wafer, a development step for developing the exposed wafer, an etching step for removing exposed members other than the portion where the resist remains by etching, and etching is completed. It is manufactured through a resist removal step for removing unnecessary resist, a device assembly step (including a dicing process, a bonding process, and a package process), an inspection step, and the like. In this case, in the lithography step, the exposure method described above is executed using the exposure apparatus of the above embodiment, and a device pattern is formed on the wafer. Therefore, a highly integrated device can be manufactured with high productivity.

20 ... main control unit, 39X _1, 39X ₂ ... X scales 39Y _1, 39Y ₂ ... Y scale, 50 ... stage device, 62a to 62f ... head unit, 64,65,67,68 ... Y head, 66 ... X Head, 70A, 70C ... Y encoder, 70B, 70D ... X encoder, 72a to 72d, 74,76 ... Z head, 100 ... Exposure device, 118 ... Interferometer system, 124 ... Stage drive system, 150 ... Encoder system, 180 ... surface position measurement system, 200 ... measurement system, PL ... projection optical system, PU ... projection unit, W ... wafer, WST ... wafer stage, WTB ... wafer table.

Claims (8)

An exposure method for continuously exposing a plurality of objects,
For each exposure of the object, the position of the moving body that moves while holding the object to be exposed is measured by the first and second position measurement systems, and the measurement result of the first position measurement system and the correction information are used. On the basis of exposing the object held by the moving body while driving the moving body,
In parallel with the exposing, creating error information about the object from an error between measurement results of the first and second position measurement systems;
Prior to exposure of an object to be exposed, in parallel with exposure processing of a plurality of objects for which exposure has been completed, out of the error information for the plurality of objects created by the creation, the magnitude of change in the error Determining a moving average of error information using the error information for an appropriate number of objects in accordance with and determining the correction information from the moving average,
By obtaining the correction information, the appropriate number is increased when the change in the error is small, and the appropriate number is decreased when the change in the error is large.   In obtaining the correction information, using a plurality of sets of error information for at least one object among the plurality of objects, a deviation from the reference information of the error information is obtained, and a minimum of the deviations is obtained. The exposure method according to claim 1, wherein the correction information is obtained from a moving average of the error information included in one set of the plurality of sets giving a square value. The error information is a set of discrete values W ^{(n ′)} _i (n ′ = 1) for a plurality of measurement points i (i >> 1) in the driving area of the moving body for each of the plurality (n) of objects. ~ N),
In obtaining the correction information, the error information W ⁽ⁿ⁾ _i for the n-th exposed object among the plurality of objects is used as the reference information, and from the ⁽ n−1) -th among the plurality of objects. Average AW ^{(n−1 to nk)} _i = (1 / k) Σ _j == of the error information W ^(n−j) _i (j = 1 to k) for the n−kth exposed object _{1 to k} W ^(n−j) _i is used to determine the deviation ε _ki = AW ^{(n−1 to n−k)} _i −W ⁽ⁿ⁾ _i with respect to k = 1 to K (K ≧ 1). The exposure method according to claim 2. In obtaining the correction information, the correction information 1 / (k + 1) Σ _j = 0 to _kW ⁽ using the value of k giving the least square value out of the deviation ε _ki (k = 1 to K). ^4. The exposure method according to claim 3, wherein ^n-j) _i is obtained.   In obtaining the correction information, each time the exposure is performed, the value of k giving the least square value is recorded, and an intermediate value of the nearest odd number of values among the recorded values is recorded. 5. The exposure method according to claim 4, wherein the exposure method is used as a value of k that gives a least square value.   The first position measurement system irradiates light from a head disposed on one of the movable body and the outside of the movable body to a measurement surface disposed on the other of the movable body and the exterior of the movable body, The exposure method according to claim 1, wherein light from the measurement surface is received to measure the position of the moving body.   The exposure method according to claim 1, wherein an interferometer is used as the second position measurement system. Forming a pattern on the object by the exposure method according to any one of claims 1 to 7,
Developing the object with the pattern formed thereon;
A device manufacturing method including: